## Withdrawal of U.S. Forces from Vietnam

The Vietnam War, a pivotal conflict during the Cold War era, involved extensive military engagement of the United States from the early 1960s, especially following the Gulf of Tonkin incident in 1964, up until 1973, when American combat troops were formally withdrawn. However, the complete withdrawal, which also marked the end of U.S. military involvement in Vietnam, notably occurred in 1975 with the fall of Saigon. This entry aims to provide a comprehensive understanding of the various phases and key events leading to the full disengagement of the United States from Vietnam by 1976.

### Background 
The Vietnam War originally began as an internal conflict between the communist North Vietnam, led by Ho Chi Minh, and the anti-communist South Vietnam. The U.S. entered the conflict with the aim of preventing a communist takeover of South Vietnam as part of its wider strategy of containment. Over the years, the war escalated into a major military engagement, drawing in neighboring countries like Laos and Cambodia and becoming increasingly unpopular domestically within the United States.

### Initial Involvement and Escalation
U.S. involvement initially began with financial and military support to the South Vietnamese government but escalated significantly after the Gulf of Tonkin incident in 1964. Following alleged attacks on U.S. naval vessels, Congress passed the Gulf of Tonkin Resolution, which gave President Lyndon B. Johnson the authority to increase U.S. military presence and conduct military operations without an official declaration of war. This led to rapid escalation, and by 1969, under President Richard Nixon, troop levels had surged to over 500,000.

### Nixon's Vietnamization Policy
The turning point in U.S. policy came with the election of President Richard Nixon in 1968, who introduced the policy of "Vietnamization," which aimed to gradually transfer all military responsibilities from U.S. forces to the South Vietnamese troops. This policy also aligned with Nixon's broader strategy to reduce U.S. military involvement overseas. Under Vietnamization, American troops began to withdraw in phases, and by 1972, the number of U.S. forces had significantly decreased.

### The Paris Peace Accords
The Paris Peace Accords, signed in January 1973, marked a critical milestone towards ending U.S. involvement in the Vietnam War. These agreements negotiated the terms for peace in Vietnam, including the withdrawal of all remaining U.S. combat troops and the return of prisoners of war. However, the peace proved ephemeral as fighting resumed between North and South Vietnam shortly after.

### The Fall of Saigon
The ultimate conclusion of U.S. military involvement came with the Fall of Saigon on April 30, 1975, when North Vietnamese forces captured the capital of South Vietnam, leading to the unification of Vietnam under communist control. This event is often referenced as marking the definitive end of the Vietnam War.

### Final Stages and Aftermath
Following the fall of Saigon, there remained a minimal U.S. military presence, primarily involved in evacuating American civilians and at-risk Vietnamese, concluding in 1976. The withdrawal represented not only a significant military retreat but also a moment of intense national reflection for the United States on its role and influence in global conflicts.

### Conclusion
The complete military withdrawal from Vietnam by 1976 marked the end of over a decade of heavy U.S. involvement in Southeast Asia. The legacy of the Vietnam War has had profound impacts on American military, political, and cultural life, shaping subsequent U.S. foreign policy and military engagements. The conflict remains a significant subject of study and reflection due to its complexity, the lessons learned, and the ongoing implications for international relations and military strategy.